WO2023054952A1 - Solventless quantum dot composition, method for producing same, and cured film, color filter, and display device comprising same - Google Patents

Abstract

The present invention relates to a solventless quantum dot composition, a method for producing same, and a cured film, a color filter, and a display device which comprise same. Specifically, the solventless quantum dot composition according to the present invention comprises quantum dots surface-modified with at least two ligands, has low viscosity and excellent optical properties, and can be produced by quantum dot (QD) synthesis followed by direct ligand substitution in the corresponding solution, thus having a simplified production process.

Description

Solvent-free quantum dot composition, method for producing the same, and cured film including the same, color filter and display device

The present invention relates to a solvent-free quantum dot composition, a method for preparing the same, and a cured film including the same, a color filter, and a display device. Specifically, the solvent-free quantum dot composition according to the present invention includes quantum dots surface-modified with two or more ligands, has low viscosity and excellent optical properties, and can be prepared by directly substituting ligands in a corresponding solution after synthesizing quantum dots (QDs). process is simplified.

Quantum dot (QD) is a so-called semiconductor nanocrystals, which can generate various colors by generating light of different wavelengths for each particle size without changing the type of material, and is said to have higher color purity and light stability than conventional light emitting materials. Due to its advantages, it is attracting attention as a next-generation light emitting device.

In particular, quantum dots, which have become a new trend in the display field, can be applied to various displays and electronic devices in addition to TVs and LEDs. Quantum dots, represented by CdSe, InP, etc., are rapidly developing in terms of luminous efficiency (Quantum Yield), and synthesis methods with luminous efficiency close to 100% have been introduced. Based on this, TVs using quantum dot sheets are currently being commercialized. As a next step, quantum dots are included in the color filter layer of the existing LED TV (pigments and dyes are excluded), and a self-emitting version of the quantum dot TV is being developed instead of filtering in the color filter layer. The core of the development of such a quantum dot TV is focused on how much light efficiency of the quantum dots can be maintained in the process of configuring the pixels and the manufacturing process.

On the other hand, materials for color filters require high sensitivity, adhesion to a substrate, chemical resistance, heat resistance, and the like. A color filter applied to a conventional display is generally formed through a patterning process in which a desired pattern is formed through an exposure process in which a photomask is applied using a photosensitive resist composition, and then the unexposed portion is dissolved and removed through a development process.

Recently, in order to solve the high quality of materials used in pixels and the resulting cost increase, a method of reducing the use of materials as much as possible by using materials only for the desired area is of interest, rather than performing patterning by spin coating or slit coating as in the past. is receiving The most representative method is the inkjet method. Since the inkjet method uses materials only for desired pixels, unnecessary waste of materials can be prevented.

However, since the viscosity of the quantum dot composition used in the inkjet method is required to be 100 cps or less, preferably 50 cps or less, a solvent is included to realize low viscosity. In this way, since the quantum dot composition includes a solvent, there is a limit in increasing the thickness or increasing the film thickness after curing, and there is a concern about environmental pollution due to the use of an organic solvent.

Accordingly, the present applicant, Hansol Chemical Co., Ltd. has applied for a solvent-free quantum dot composition, a manufacturing method thereof, and a cured film including the same, a color filter, and a display device (No. 10-2021-0011711). This was a quantum dot composition that does not contain a solvent, has a low viscosity and has excellent optical properties, and a method for manufacturing the same.

The above-described prior filed invention had to use separated and purified quantum dot powder in the same way as other conventional methods for ligand substitution on the surface of quantum dots during the manufacturing process. In order to separate and purify the synthesized quantum dots, it was found that at least two centrifugation processes were required, which made the process somewhat complicated and added cost accordingly.

Therefore, the problem to be solved by the present invention is to use the solution in which the quantum dots are synthesized as it is in the ligand substitution process without a separation and purification process such as centrifugation, thereby simplifying the process, reducing the cost accordingly, and providing excellent light efficiency and lower viscosity. It is to provide a solvent-free quantum dot composition and a manufacturing method thereof.

Another problem to be solved in the present invention is to provide a cured film containing the solvent-free quantum dot composition, a color filter and a display device.

According to one aspect of the present invention for solving the above problems,

(a) synthesizing quantum dots;

(b) first surface-modifying the quantum dots with a primary ligand having an ethylene glycol structure without separating the quantum dots from the solution in which the quantum dots were synthesized;

(c) secondarily surface-modifying the first surface-modified quantum dots with a second ligand represented by Chemical Formula 1 below;

[Formula 1]

(In Formula 1 above,

M is a divalent to tetravalent metal;

R ¹ to R ³ are independently hydrogen or an organic group having 3 to 70 carbon atoms;

n is an integer from 2 to 4.)

(d) obtaining surface-modified quantum dots from the product of step (c); and

(e) dispersing the surface-modified quantum dots obtained above in a photopolymerizable monomer;

Preferably, after step (c),

(f) tertiary surface modification of the modified quantum dots by adding a tertiary ligand having 3 to 40 carbon atoms including a carboxyl group;

Preferably, the primary ligand has a molecular weight of 100 g / mol to 500 g / mol, and provides a method for producing a solvent-free quantum dot composition, characterized in that it comprises an ethylene glycol structure in 1 to 5 repeating units.

Preferably, at least one of R ¹ to R ³ in Formula 1 repeatedly includes an ethylene glycol structure,

The number of repeating units of the total ethylene glycol structure included in R ¹ to R ³ is 2 to 15,

It provides a method for producing a solvent-free quantum dot composition, characterized in that an organic group of C1 to C15 is bonded to the terminal of the ethylene glycol structure.

Preferably, the tertiary ligand provides a method for preparing a solvent-free quantum dot composition represented by Formula 2 below.

[Formula 2]

(In Formula 2 above,

L is a single bond or is selected from the group consisting of a substituted or unsubstituted C1 to C20 alkylene group and a substituted or unsubstituted C1 to C20 alkenylene group;

A is a single bond, or ester (-C(=O)O-), ether (-O-), carbonyl (-C(=O)-), sulfonyl (-SO ₂ -), sulfide (- A C1 to C20 alkylene or alkenylene group containing at least one functional group selected from the group consisting of S-) and sulfoxide (-SO-),

R is hydrogen or is selected from the group consisting of a substituted or unsubstituted C1 to C20 alkyl group and a substituted or unsubstituted C1 to C20 alkenyl group.)

Preferably, the mixing ratio of the quantum dots and all ligands is 1:1 to 1:20 by weight, providing a method for producing a solvent-free quantum dot composition.

Preferably, the molar ratio of the primary ligand and the secondary ligand added to the solution is 1:1 to 1:20, providing a method for producing a solvent-free quantum dot composition.

Preferably, the molar ratio of the primary ligand, secondary ligand and tertiary ligand added to the solution is 1: 1 to 20: 1 to 30, providing a method for producing a solvent-free quantum dot composition.

Preferably, the primary ligand is from the group consisting of methoxy triethylene glycol thioglycolate and 2-(2-methoxyethoxy)acetic acid Provides a method for producing one or more selected, solvent-free quantum dot compositions.

Preferably, the secondary ligand is zinc-(3-methoxybutyl 3-mercaptopropionate) ₂ (Zn-(3-methoxybutyl 3-mercaptopropionate) ₂ ), zinc-(3-methoxybutyl thioglycolic acid) ₂ (Zn-(3-methoxybutyl thioglycolate) ₂ ), zinc-(2-ethylhexyl thioglycolate) ₂ (Zn-(2-ethylhexyl thioglycolate) ₂ ), zinc-(butyl mercaptopropionic acid) ₂ (Zn-( butyl mercaptopropionate) ₂ ), zinc-(isopropyl mercaptopropionate) ₂ (Zn-(isopropyl mercaptopropionate) ₂ ), zinc-(bis-(butoxy triethylene glycol) mercapto succinic acid) ₂ (Zn-(Bis-( butoxy triethylene glycol)mercapto succinate) ₂ ) and zinc-(poly(ethylene glycol)methyl ether-thioglycolic acid) ₂ (Zn-(poly(ethylene glycol)methyl ether-thioglycolate) ₂ ) At least one selected from the group consisting of, It provides a method for preparing a solvent-free quantum dot composition.

Preferably, the tertiary ligand is 2-carboxyethyl acrylate, mono-2-(acryloyloxy)ethyl succinate, mono-2-( methacryloyloxy)ethyl succinate, mono-2-(methacryloyloxy)ethyl maleate, 2-[2 -(2-methoxyethoxy)ethoxy]acetic acid (2-[2-(2-methoxyethoxy)ethoxy]acetic acid) and 2-(2-methoxyethoxy)acetic acid acid) provides a method for producing a solvent-free quantum dot composition, which is at least one selected from the group consisting of

Preferably, the solution contains fatty acids, fatty acid derivatives, by-products of the quantum dot synthesis reaction, dioctyl octadecenamide, trioctylphosphine and its oxides, n-octadecene, tri Octylamine, metal acetate, metal oleate, tris(trimethylsilyl)phosphine, selenium (Se), sulfur (S), selenium-trioctylphosphine, sulfur-trioctylphos It provides a method for producing a solvent-free quantum dot composition comprising at least one selected from the group consisting of pin, chloride salt and metal chloride.

Preferably, the photopolymerizable monomer is 1,6-hexanediol diacrylate, and a method for preparing a solvent-free quantum dot composition is provided.

In another aspect of the invention,

Including quantum dots and photopolymerizable monomers,

The quantum dots may include a primary ligand including an ethylene glycol structure; and

A secondary ligand represented by Formula 1 below: Provides a solvent-free quantum dot composition that is surface-modified with.

[Formula 1]

(In Formula 1 above,

M is a divalent to tetravalent metal;

R ¹ to R ³ are independently hydrogen or an organic group having 3 to 70 carbon atoms;

n is an integer from 2 to 4.)

Preferably, the surface-modified quantum dot provides a solvent-free quantum dot composition that is surface-modified with a tertiary ligand having 3 to 40 carbon atoms including a carboxyl group.

Preferably, the surface modification of the quantum dots provides a solvent-free quantum dot composition, characterized in that made in a solution in which the quantum dots are synthesized.

Preferably, the primary ligand has a molecular weight of 100 g/mol to 500 g/mol, and provides a solvent-free quantum dot composition comprising an ethylene glycol structure in 1 to 5 repeating units.

Preferably, at least one of R ¹ to R ³ in Formula 1 repeatedly includes an ethylene glycol structure,

The number of repeating units of the total ethylene glycol structure included in R ¹ to R ³ is 2 to 15,

It provides a solvent-free quantum dot composition characterized in that an organic group of C1 to C15 is bonded to the terminal of the ethylene glycol structure.

Preferably, the tertiary ligand provides a solvent-free quantum dot composition represented by Formula 2 below.

[Formula 2]

(In Formula 2 above,

L is a single bond or is selected from the group consisting of a substituted or unsubstituted C1 to C20 alkylene group and a substituted or unsubstituted C1 to C20 alkenylene group;

A is a single bond, or ester (-C(=O)O-), ether (-O-), carbonyl (-C(=O)-), sulfonyl (-SO ₂ -), sulfide (- A C1 to C20 alkylene or alkenylene group containing at least one functional group selected from the group consisting of S-) and sulfoxide (-SO-),

R is hydrogen or is selected from the group consisting of a substituted or unsubstituted C1 to C20 alkyl group and a substituted or unsubstituted C1 to C20 alkenyl group.)

Preferably, the primary ligand is from the group consisting of methoxy triethylene glycol thioglycolate and 2-(2-methoxyethoxy)acetic acid Provides one or more selected, solvent-free quantum dot compositions.

Preferably, the secondary ligand is zinc-(3-methoxybutyl 3-mercaptopropionate) ₂ (Zn-(3-methoxybutyl 3-mercaptopropionate) ₂ ), zinc-(3-methoxybutyl thioglycolic acid) ₂ (Zn-(3-methoxybutyl thioglycolate) ₂ ), zinc-(2-ethylhexyl thioglycolate) ₂ (Zn-(2-ethylhexyl thioglycolate) ₂ ), zinc-(butyl mercaptopropionic acid) ₂ (Zn-( butyl mercaptopropionate) ₂ ), zinc-(isopropyl mercaptopropionate) ₂ (Zn-(isopropyl mercaptopropionate) ₂ ), zinc-(bis-(butoxy triethylene glycol) mercapto succinic acid) ₂ (Zn-(Bis-( butoxy triethylene glycol)mercapto succinate) ₂ ) and zinc-(poly(ethylene glycol)methyl ether-thioglycolic acid) ₂ (Zn-(poly(ethylene glycol)methyl ether-thioglycolate) ₂ ) At least one selected from the group consisting of, A solvent-free quantum dot composition is provided.

Preferably, the tertiary ligand is 2-carboxyethyl acrylate, mono-2-(acryloyloxy)ethyl succinate, mono-2-( methacryloyloxy)ethyl succinate, mono-2-(methacryloyloxy)ethyl maleate, 2-[2 -(2-methoxyethoxy)ethoxy]acetic acid (2-[2-(2-methoxyethoxy)ethoxy]acetic acid) and 2-(2-methoxyethoxy)acetic acid acid) to provide a solvent-free quantum dot composition that is at least one selected from the group consisting of.

Preferably, M is Mg, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Sr, Mo, Pd, Cd, In or Sn, solvent-free A quantum dot composition is provided.

Preferably, the M is Zn, providing a solvent-free quantum dot composition.

Preferably, the molar ratio of the primary ligand to the secondary ligand is 1:1 to 1:20, providing a solvent-free quantum dot composition.

Preferably, the molar ratio of the primary ligand, secondary ligand and tertiary ligand is 1: 1 to 20: 1 to 30, providing a solvent-free quantum dot composition.

Preferably, the composition ratio of the quantum dots and the ligand is 1:1 to 1:20 by weight, providing a solvent-free quantum dot composition.

Preferably, the photopolymerizable monomer is a (meth)acrylate-based monomer, providing a solvent-free quantum dot composition.

Preferably, the photopolymerizable monomer is 1,6-hexandiol diacrylate, providing a solvent-free quantum dot composition.

Preferably, a solvent-free quantum dot composition having a viscosity of 30 cps or less is provided.

Preferably, a solvent-free quantum dot composition used for inkjet printing is provided.

Preferably, a cured film prepared using the solvent-free quantum dot composition is provided.

Preferably, when the solvent-free quantum dot composition is coated to a thickness of 10 ± 0.5 μm, a cured film having an absolute quantum efficiency of 30% or more is provided.

Preferably, a color filter including the solvent-free quantum dot composition is provided.

Preferably, a display device including the color filter is provided.

In the past, it was difficult to modify the surface of quantum dots by directly injecting a ligand in the presence of a solvent for quantum dot synthesis and its residue without separating and purifying the quantum dots through an additional process after quantum dot synthesis, but the solvent-free type according to the present invention The quantum dot composition and its manufacturing method have advantages that enable this, and thus process simplification and cost reduction are achieved.

The solvent-free quantum dot composition according to the present invention may exhibit excellent miscibility between quantum dots and monomers without including a solvent. In addition, since the solvent-free quantum dot composition according to the present invention has excellent optical properties and low viscosity, it can be used for inkjet printing.

Hereinafter, the present invention will be described.

All terms (including technical and scientific terms) used in this specification, unless otherwise defined, may be used in a meaning commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in commonly used dictionaries are not interpreted ideally or excessively unless explicitly specifically defined.

In addition, throughout this specification, when a certain component is said to "include", it means that it may further include other components, not excluding other components, unless otherwise stated.

In addition, in this specification, “(meth)acrylate” represents acrylate and methacrylate, “(meth)acryl” represents acryl and methacryl, and “(meth)acryloyl” represents acryloyl. and methacryloyl.

In addition, in this specification, "monomer" and "monomer" have the same meaning. Monomers in the present invention are distinguished from oligomers and polymers and refer to compounds having a weight average molecular weight of 1,000 or less. In this specification, "photopolymerizable monomer" refers to a functional group involved in polymerization, such as a (meth)acrylate group.

In this specification, "substitution" means that hydrogen in a compound or functional group is a C1 to C30 alkyl group, a C2 to C30 alkenyl group, a C2 to C30 alkynyl group, a C1 to C30 alkoxy group, a C1 to C30 heteroalkyl group, a C3 to C30 heteroalkylaryl group, C3 to C30 cycloalkyl group, C3 to C15 cycloalkenyl group, C6 to C30 cycloalkynyl group, C2 to C30 heterocycloalkyl group, halogen (-F, -Cl, -Br or -I), a hydroxyl group (-OH), a nitro group (-NO ₂ ), a cyano group (-CN), an ester group (-C(=O)OR), where R is a C1 to C10 alkyl group or an alkenyl group), Ether group (-OR, where R is a C1 to C10 alkyl or alkenyl group), carbonyl (-C(=O)-R, where R is a C1 to C10 alkyl or alkenyl group), carboxyl group (-COOH) And means substituted with a substituent selected from combinations thereof.

In this specification, "organic group" means a C1 to C30 straight chain or branched chain alkyl group, a C2 to C30 straight chain or branched chain alkenyl group, or a C2 to C30 straight chain or branched chain alkynyl group. In addition, the alkyl group, alkenyl group, and alkynyl group may be substituted or unsubstituted, respectively.

In this specification, “alkyl” means a monovalent substituent derived from a straight or branched chain saturated hydrocarbon having 1 to 40 carbon atoms. Examples thereof include, but are not limited to, methyl, ethyl, propyl, isobutyl, sec-butyl, pentyl, iso-amyl, hexyl, and the like.

In this specification, "alkenyl" means a monovalent substituent derived from a straight-chain or branched chain unsaturated hydrocarbon having 2 to 40 carbon atoms and having at least one carbon-carbon double bond. Examples thereof include, but are not limited to, vinyl, allyl, isopropenyl, and 2-butenyl.

<Solvent-free quantum dot composition>

The quantum dot composition according to an embodiment of the present invention is a solvent-free quantum dot composition, and specifically, even if it does not contain a solvent, it has low viscosity and excellent optical properties, so it can be applied to inkjet printing.

For example, a solvent-free quantum dot composition comprising quantum dots and a photopolymerizable monomer, wherein the quantum dots are surface-modified with a primary ligand containing an ethylene glycol structure and a secondary ligand represented by Formula 1 below provides

In addition, it includes quantum dots and photopolymerizable monomers, and the quantum dots are surface-modified with a primary ligand having an ethylene glycol structure, a secondary ligand represented by Formula 1 below, and a tertiary ligand having 3 to 40 carbon atoms including a carboxyl group. A phosphorus, solvent-free quantum dot composition is provided.

[Formula 1]

(In Formula 1 above,

M is a divalent to tetravalent metal;

R ¹ to R ³ are independently hydrogen or an organic group having 3 to 70 carbon atoms;

n is an integer from 2 to 4.)

In addition, in the solvent-free quantum dot compositions, the surface modification of the quantum dots may be performed in a solution in which the quantum dots are synthesized.

Hereinafter, a detailed composition of the quantum dot composition is as follows.

quantum dot

Quantum Dot (QD) is a nano-sized semiconductor material, and may have different energy band gaps depending on its size and composition, and thus emit light of various emission wavelengths.

These quantum dots have a homogeneous monolayer structure; a multilayer structure such as a core-shell type, a gradient structure, and the like; or a mixture thereof. When the shell has multiple layers, each layer may contain components different from each other, such as (semi)metal oxides.

The quantum dot (QD) may be freely selected from a group II-VI compound, a group III-V compound, a group IV-VI compound, a group IV element, a group IV compound, and combinations thereof. When the quantum dot is in the core-shell form, the core and the shell may be freely composed of the components exemplified below, respectively.

In one example, the II-VI compound is a binary element compound selected from the group consisting of CdO, CdS, CdSe, CdTe, ZnO, ZnS, ZnSe, ZnTe, HgS, HgSe, HgTe, MgSe, MgS, and mixtures thereof; A ternary selected from the group consisting of CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS and mixtures thereof bovine compounds; and CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, and quaternary compounds selected from the group consisting of mixtures thereof.

In another example, the group III-V compound is a binary element compound selected from the group consisting of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, and mixtures thereof; A ternary compound selected from the group consisting of GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, and mixtures thereof; And it may be selected from the group consisting of quaternary compounds selected from the group consisting of GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, and mixtures thereof. there is.

In another example, the group IV-VI compound is a binary compound selected from the group consisting of SnS, SnSe, SnTe, PbS, PbSe, PbTe, and mixtures thereof; a ternary compound selected from the group consisting of SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, and mixtures thereof; And it may be selected from the group consisting of quaternary compounds selected from the group consisting of SnPbSSe, SnPbSeTe, SnPbSTe, and mixtures thereof.

In another example, the group IV element may be selected from the group consisting of Si, Ge, and mixtures thereof. The group IV compound may be a binary element compound selected from the group consisting of SiC, SiGe, and mixtures thereof.

The above-mentioned two-element compound, three-element compound, or quaternary element compound may be present in the particle at a uniform concentration, or may be present in the same particle in a state in which the concentration distribution is partially different. Also, one quantum dot may have a core/shell structure surrounding another quantum dot. The interface between the core and the shell may have a concentration gradient in which the concentration of elements present in the shell decreases toward the center.

The shape of the quantum dot is not particularly limited as long as it is a shape commonly used in the art. For example, spherical, rod-shaped, pyramidal, disc-shaped, multi-arm, or cubic nanoparticles, nanotubes, nanowires, nanofibers, nanoplatelet particles etc. can be used.

In addition, the size of the quantum dots is not particularly limited and may be appropriately adjusted within a common range known in the art. For example, the average particle diameter (D50) of the quantum dots may be about 2 to 10 nm. In this way, when the particle diameter of the quantum dots is controlled to be in the range of about 2 to 10 nm, light of a desired color can be emitted. For example, when the particle diameter of the quantum dot core/shell containing InP is about 5 to 6 nm, light having a wavelength of about 520 to 550 nm can be emitted, while the particle diameter of the quantum dot core/shell containing InP is about In the case of 7 to 8 nm, light of about 620 to 640 wavelengths can be emitted. For example, as the blue-emitting QD (Quantum dot), a non-cadmium (Cd) group III-V QD (eg, InP, InGaP, InZnP, GaN, GaAs, GaP) can be used.

In addition, the quantum dots may have a full width of half maximum (FWHM) of an emission wavelength spectrum of about 40 nm or less, and color purity or color reproducibility may be improved within this range. In addition, since light emitted through the quantum dots is emitted in all directions, a wide viewing angle may be improved.

According to one embodiment of the present invention, the content of the quantum dot may be 1 to 60% by weight, preferably 20 to 50% by weight based on the total weight of the solvent-free quantum dot composition.

ligand

In the solvent-free quantum dot composition according to the present invention, the ligand serves to modify the surface of the quantum dots. Quantum dots have a barrier to dispersal to photopolymerizable monomers due to their hydrophobic surface properties, and the miscibility of quantum dots to photopolymerizable monomers can be improved by modifying the surface of quantum dots with appropriate ligands.

According to one embodiment of the present invention, the ligand may include a primary ligand including an ethylene glycol structure and a secondary ligand represented by Chemical Formula 1 below.

According to one embodiment of the present invention, the ligand may include a primary ligand having an ethylene glycol structure, a secondary ligand represented by Chemical Formula 1 below, and a tertiary ligand having 3 to 40 carbon atoms including a carboxyl group.

The primary ligand is introduced into the solution in which the quantum dot is synthesized and first modifies the surface of the hydrophobic quantum dot so that the surface of the quantum dot has a slight polarity. Facilitates substitution of secondary ligands.

[Formula 1]

In Formula 1, M is a divalent to tetravalent metal, and R ¹ to R ³ are independently hydrogen or an organic group having 3 to 70 carbon atoms, and n is an integer of 2 to 4.

In general, the solvents used in the production of quantum dots are hydrophobic (for example, solvents such as 1-Octadecene, n-octadecene, and trioctyl amine are used), and various synthetic residues are present in the solution in which the quantum dots are synthesized. (For example, fatty acids such as oleic acid, fatty acid derivatives such as octyl oleate, other by-products such as dioctyl octadecenamide, trioctylphosphine and its oxides, solvents such as n-octadecene or trioctyl amine, metal acetate, metal oleate, tris(trimethylsilyl)phosphide Since pin, Se, S, Se-trioctylphosphine, S-trioctylphosphine, chloride salt, metal chloride, etc.) are mixed, most of the metal-thiol ligands are included immediately without separation and purification of quantum dots. It was difficult to modify the surface of the quantum dots with the ligands of . However, in one embodiment of the present invention, after modifying the quantum dots with a primary ligand containing an ethylene glycol structure in the solution in which the quantum dots are synthesized, even in the solution after the synthesis of the quantum dots in which residual impurities exist, a metal-thiol ligand containing Modification of other ligands is readily possible.

The primary ligand preferably has a molecular weight of 100 g / mol to 500 g / mol, more preferably has a molecular weight of 100 g / mol to 500 g / mol and comprises an ethylene glycol structure with 1 to 5 repeating units. can Specifically, at least one selected from the group consisting of methoxy triethylene glycol thioglycolate (hereinafter referred to as MTEGT) and 2-(2-Methoxyethoxy)acetic acid (hereinafter referred to as MEAA) may be used, and preferably MTEGT may be used. If the molecular weight of the primary ligand is too large, it may be disadvantageous to primary surface modification.

The secondary ligand may be a metal-thiol-based compound formed by reacting a metal salt with a thiol-based compound.

In the secondary ligand, M is a divalent to tetravalent metal. For example, M is a group 2 to 14 metal, Mg, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Sr, Y, Zr, It may be Nb, Mo, Tc, Ru, Rh, Pd, Cd, In or Sn, preferably Zn. In Formula 1, n is determined according to the valence of M and is an integer of 2 to 4.

In Formula 1 representing the secondary ligand, at least one of R ¹ to R ³ repeatedly includes an ethylene glycol structure, and the total number of repeating units of the ethylene glycol structure included in R ¹ to R ³ is 2 to 15, , It may be characterized in that an organic group of C1 to C15 is bonded to the terminal of the ethylene glycol structure.

In addition, at least one of R ¹ to R ³ in Formula 1 may be an organic group having 3 to 20 carbon atoms. For example, ester (-C(=O)O-), ether (-O-), carbonyl (-C(=O)-), carboxyl group (-C(=O)-OH), sulfonyl ( -SO ₂ -), sulfide (-S-) and sulfoxide (-SO-), alkoxy group (C _n H _2n+1 O-), hydroxy group (-OH) containing at least one functional group selected from the group consisting of may be an alkylene group or an alkenylene group having 3 to 20 carbon atoms. Specifically, R ¹ is an organic group having 4 to 15 carbon atoms including an ester (-C(=O)O-) functional group, and R ² and R ³ may be formed of hydrogen.

Since the thiol group in the secondary ligand has excellent affinity with the surface of the quantum dots, the dispersibility of the quantum dots in the photopolymerizable monomer can be improved. In addition, the secondary ligand includes not only a thiol group, but also an ester, ether, carbonyl, carboxyl group, alkoxy group, cycloalkyl group, or hydroxy group, thereby maximizing the dispersibility of the surface-modified quantum dot to a polar monomer having hydrophobicity. . In addition, a quantum dot composition including such quantum dots may have advantageous characteristics (eg, low viscosity) for a display process. On the other hand, when using a thiol-based compound having 3 or less carbon atoms, surface modification of quantum dots is possible, but due to the high polarity of surface-modified quantum dots, dispersion in common solvents and monomers may be difficult.

The secondary ligand is specifically Zn-(3-methoxybutyl 3-mercaptopropionate) ₂ , Zn-(3-methoxybutyl thioglycolate) ₂ , Zn-(2-ethylhexyl thioglycolate) ₂ , Zn-(butyl mercaptopropionate) _2, Zn-( isopropyl mercaptopropionate) _2, Zn-(Bis-(butoxy triethylene glycol)mercapto succinate) ₂ and Zn-(poly(ethylene glycol)methyl ether-thioglycolate) ₂ may be at least one selected from the group consisting of.

The tertiary ligand may have 3 to 40 carbon atoms and include a carboxyl group. Also, according to an embodiment of the present invention, the tertiary ligand may not include a thiol group.

According to one embodiment of the present invention, the tertiary ligand may be represented by Formula 2 below.

[Formula 2]

In Formula 2,

L is a single bond or is selected from the group consisting of a substituted or unsubstituted C1 to C20 alkylene group and a substituted or unsubstituted C1 to C20 alkenylene group;

A is a single bond, or ester (-C(=O)O-), ether (-O-), carbonyl (-C(=O)-), sulfonyl (-SO ₂ -), sulfide (- A C1 to C20 alkylene or alkenylene group containing at least one functional group selected from the group consisting of S-) and sulfoxide (-SO-),

R is hydrogen or is selected from the group consisting of a substituted or unsubstituted C1 to C20 alkyl group and a substituted or unsubstituted C1 to C20 alkenyl group.

Preferably, A in the tertiary ligand may include an ester (-COO-), an ether (-O-), or a combination thereof. In addition, A may be a C2 to C15 alkylene group or alkenylene group, preferably a C2 to C10 alkylene group or alkenylene group.

The tertiary ligand is specifically 2-carboxyethyl acrylate, mono-2-(acryloyloxy)ethyl succinate, mono-2-(methacryloyloxy)ethyl succinate, mono-2-(methacryloyloxy)ethyl maleate, 2-[2-(2- It may be at least one selected from the group consisting of methoxyethoxy)ethoxy]acetic acid and 2-(2-methoxyethoxy)acetic acid.

In general, thiol-based ligands are known to have high reactivity with the surface of quantum dots. However, quantum dot compositions containing only thiol-based ligands are not suitable for use in inkjet compositions because they generate harmful odors (gases) or deteriorate storage stability due to increased viscosity. The quantum dot composition according to the present invention exhibited low viscosity and excellent storage stability (degree of change in QE value before and after heat treatment) by using a secondary ligand containing a thiol-based ligand and a tertiary ligand not containing a thiol group together. In addition, the tertiary ligands are ester (-C(=O)O-), ether (-O-), carbonyl (-C(=O)-), carboxyl group (-C(=O)-OH), etc. By including the functional group of the excellent dispersibility to the photopolymerizable monomer. On the other hand, when the number of carbon atoms of the tertiary ligand is 16 or more, the surface of the quantum dot may not be modified or dispersibility in common solvents and monomers may be impaired.

When both the primary ligand and the secondary ligand repeatedly include an ethylene glycol structure, the viscosity and optical properties of the ink composition may be excellent compared to cases where the ethylene glycol structure is not included. This seems to be because the dispersibility of QDs in the composition is further improved because ethylene glycol has strong hydrophilicity due to its structural characteristics.

According to one embodiment of the present invention, the molar ratio of the primary ligand and the secondary ligand is 1: 1 to 20, preferably 1: 1 to 10 molar ratio, more preferably 1: 1 to 5 molar ratio, but Not limited to this.

In addition, according to one embodiment of the present invention, the molar ratio of the primary ligand, secondary ligand and tertiary ligand is 1: 1 to 20: 1 to 30, preferably 1: 1 to 10: 1 to 15 molar ratio, More preferably, it may be 1: 1 to 5: 1 to 8, but is not limited thereto.

In addition, according to one embodiment of the present invention, the mixing ratio of the quantum dots and the ligand may be 1: 1 to 20 weight ratio, preferably 1: 1 to 10 weight ratio, more preferably 1: 5 to 10. Here, the ligand means the sum of a primary ligand and a secondary ligand or a sum of a primary ligand, a secondary ligand and a tertiary ligand.

photopolymerizable monomer

In the quantum dot composition according to the present invention, the photopolymerizable monomer serves to express the structure and physical properties of the matrix by controlling the total crosslinking density of the formulation in which the quantum dots (QDs) are dispersed, that is, the polymer matrix. In addition, it is possible to improve flexibility and adhesion and adhesion to other materials.

The photopolymerizable monomer may include a (meth)acrylate-based monomer. Any monomer that can be used can be used without particular limitation as long as it is a monomer commonly used in the art.

For example, the (meth)acrylate-based monomer may include at least one of a (meth)acrylic group, a vinyl group, and an allyl group. Specifically, 1,6-hexanediol diacrylate, 1,6-cyclohexanediol diacrylate, 2,2-dimethyl-1 ,3-propanediol diacrylate (2,2-dimethyl-1,3-propanediol diacylate), diethylene glycol diacrylate, dipropylene glycol diacrylate, 1, 3-butylene glycol dimethacrylate, trimethylolpropane trimethacrylate, isobornyl acrylate, isobornyl methacrylate , tetrahydrofuryl acrylate, acryloyl morpholine, 2-phenoxyethyl acrylate, tripropylene glycol diacrylate, trimethylolpropane Trimethylolpropane triacrylate, pentaerythritol mono(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate , dipentaerythritol hexaacrylate and dipentaerythritol hexamethacrylate. These may be used alone or in combination of two or more. In the present invention, 1,6-hexanediol diacrylate as a photopolymerizable monomer is preferable to achieve the viscosity characteristics of the solvent-free quantum dot composition.

In the present invention, the content of the (meth)acrylamide-based monomer may be 35 to 80% by weight, preferably 45 to 70% by weight based on the total weight of the solvent-free quantum dot composition.

photoinitiator

In the solvent-free quantum dot composition according to the present invention, the photoinitiator is a component that is excited by a light source such as ultraviolet (UV) and serves to initiate photopolymerization, and a conventional photopolymerization photoinitiator in the art may be used without limitation. For example, an acetophenone-based compound, a benzophenone-based compound, a thioxanthone-based compound, a benzoin-based compound, a triazine-based compound, an oxime-based compound, and the like may be used.

Non-limiting examples of usable photoinitiators include Ethyl (2,4,6-trimethylbenzoyl) phenylphosphinate, Irgacure 184, Irgacure 369, Irgacure 651, Irgacure 819, Irgacure 907, Benzionalkylether, Benzophenone ), Benzyl dimethyl katal, Hydroxycyclohexyl phenyl acetone, Chloroacetophenone, 1,1-Dichloro acetophenone, Diethoxyacetophenone (Diethoxy acetophenone), Hydroxy Acetophenone, 2-Chloro thioxanthone, 2-ETAQ (2-EthylAnthraquinone), 1-hydroxy-cyclohexyl-phenyl-ketone (1- Hydroxy- cyclohexyl-phenyl-ketone), 2-hydroxy-2-methyl-1-phenyl-1-propanone (2-Hydroxy-2- methyl-1-phenyl-1-propanone), 2-hydroxy-1 -[4-(2-hydroxyethoxy)phenyl]-2-methyl-1-propanone (2-Hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methyl-1-propanone), and methylbenzoylformate. These may be used alone or in combination of two or more.

The amount of the photoinitiator may be appropriately adjusted within a range known in the art. For example, it may be 0.01 to 10% by weight, preferably 0.1 to 5% by weight based on the total weight of the solvent-free quantum dot composition. When the content of the photoinitiator falls within the aforementioned range, photopolymerization may be sufficiently performed without deterioration of physical properties of the matrix.

diffuser

In the solvent-free quantum dot composition according to the present invention, the diffusion agent reflects light not absorbed by the light conversion material, and allows the light conversion material to absorb the reflected light again. That is, the diffusion agent may increase light conversion efficiency by increasing the amount of light absorbed by the light conversion material.

As the diffusion agent, any diffusion agent component known in the art may be used without limitation. The dispersing agent may be in a solid form such as a powder or may be a dispersion in which the dispersing agent is dispersed.

Non-limiting examples of usable diffusing agents include barium sulfate (BaSO ₄ ), calcium carbonate (CaCO ₃ ), titanium dioxide (TiO ₂ ), zirconia (ZrO ₂ ), or a combination thereof. In addition, the average particle diameter or shape of the diffusing agent is not particularly limited, and may be appropriately selected from configurations known in the art. For example, the average particle diameter (D50) may be 150 nm to 250 nm, specifically 180 nm to 230 nm. When the average particle diameter of the diffusing agent is within the above range, a superior light diffusing effect may be obtained and light conversion efficiency may be increased.

The content of the diffusing agent may be appropriately adjusted within a range known in the art. For example, it may be 0.01 to 10% by weight, preferably 0.1 to 5% by weight based on the total weight of the solvent-free quantum dot composition. When the content of the diffusion agent falls within the above-mentioned range, the effect of improving light conversion efficiency may be exhibited without deterioration of physical properties of the matrix.

polymerization inhibitor

In the solventless quantum dot composition according to the present invention, the polymerization inhibitor reacts with radicals to form radicals or compounds of low reactivity that cannot cause polymerization, and can control the rate of photopolymerization.

As the polymerization inhibitor, materials known in the art may be used without limitation. For example, as the polymerization inhibitor, quinone-based compounds, phenol or aniline-based compounds, and aromatic nitro and nitroso compounds may be used. Specifically, hydroquinone (HQ), methylhydroquinone (THQ), hydroquinone monomethyl ether (MEHQ) and hydroquinone monoethyl ether (EEHQ), 1,4-benzoquinone (BQ), 2,5-diphenylbenzo quinone (DPBQ), methyl-1,4-benzoquinone (MBQ), phenyl-1,4-benzoquinone (PBQ); 2,6-di-tert-butyl-4-methylphenol (BHT), 2,6-diphenyl-4-octadecyloxyphenol, catechol; phenocyazine, bis(α-methylbenzyl)phenocyazine, 3,7-dioctylphenocyazine, bis(α,α-dimethylbenzyl)phenocyazine; Dimethyldithiocarbamic acid, diethyldithiocarbamic acid, dipropyldithiocarbamic acid, dibutyldithiocarbamic acid, and diphenyldithiocarbamic acid. These may be used alone or in combination of two or more.

The content of the polymerization inhibitor may be appropriately adjusted within a range known in the art. For example, it may be 0.01 to 2% by weight, preferably 0.05 to 1% by weight based on the total weight of the solvent-free quantum dot composition.

stabilizator

In the solvent-free quantum dot composition according to the present invention, a stabilizer may be added to improve stability and dispersibility of the quantum dots. The stabilizer may stabilize the quantum dots by substituting the shell surface of the quantum dots to improve dispersion stability of the quantum dots in a solvent.

Any stabilizer that can be used in the art can be used without limitation as long as it can improve the stability and dispersibility of quantum dots, and for example, a thiol-based stabilizer can be used. The thiol-based stabilizer may improve the dispersibility of the quantum dots with respect to the photopolymerizable monomer. In addition, the thiol group of the thiol-based stabilizer reacts with the acryl group of the photopolymerizable monomer to form a covalent bond, thereby improving heat resistance of the quantum dot composition.

The thiol-based stabilizer may have 7 or more carbon atoms, and may have 2 to 10, for example, 2 to 6 thiol groups (-SH) at the terminal depending on its structure, but is not particularly limited thereto. Non-limiting examples of usable thiol-based stabilizers include pentaerythritol tetrakis (3-mercaptopropionate), trimethylolpropane tris (3-mercaptopropionate) ( trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetrakis(mercaptoacetate), trimethylolpropane tris(2-mercaptoacetate), glycol di -3-mercaptopropionate (Glycol di-3-mercaptopropionate), or mixtures thereof.

Other Additives

In addition to the components described above, the quantum dot composition of the present invention may use additives known in the art without limitation within a range that does not impair the effects of the present invention. At this time, the content of the additive may be appropriately adjusted within a range known in the art.

Examples of usable additives include silane-based compounds, siloxane-based compounds, antioxidants, polymerization inhibitors, lubricants, surface conditioners, surfactants, adhesion promoters, antifoaming agents, slip agents, solvents, wetting agents, light stabilizers, stain inhibitors, softeners, There are thickeners, polymers, and the like. These may be used alone or in combination of two or more.

The silane-based compound serves to impart adhesiveness to the matrix, and the siloxane-based compound serves to impart wettability. Components known in the art may be used as the silane-based compound and the siloxane-based compound without limitation.

Antioxidants suppress discoloration due to heat or light irradiation and discoloration due to various oxidizing gases such as ozone, active oxygen, NOx, and SOx (X is an integer), and in the present invention, by adding antioxidants, matrix coloration is prevented. It is possible to reduce the decrease in film thickness due to decomposition. Examples of usable antioxidants include hydrazides, hindered amine-based antioxidants, nitrogen-containing heterocyclic mercapto-based compounds, thioether-based antioxidants, hindered phenol-based antioxidants, ascorbic acids, zinc sulfate, and thiocyanic acid. Salts, thiourea derivatives, sugars, nitrites, sulfites, thiosulfates, hydroxylamine derivatives, and the like.

A leveling agent may be included for the purpose of further increasing the adhesive strength in the composition by leveling the quantum dot composition so that the quantum dot composition can be coated flatly and smoothly. The leveling agent may include acrylic, silicone, or the like alone or in combination of two or more. For example, polyether-modified polydimethylsiloxane may be included, and a (meth)acryloyl group may be added to the polyether chain.

A surfactant may be included for mixing and coating uniformity of the quantum dot composition. As the surfactant, conventional cationic, anionic, and nonionic surfactants known in the art may be used, and for example, one or more of fluorine-based surfactants, silicone-based surfactants, and fluorosilicone-based surfactants may be used.

The light stabilizer is an ultraviolet absorber and has an effect of increasing the weatherability of the matrix. The softening agent is for relieving cracks in the dried polymer matrix, and can improve impact resistance and bending resistance by mitigating cracks in the cured matrix.

The solvent-free quantum dot composition according to the present invention includes quantum dots surface-modified with two or more ligands and a photopolymerizable monomer having excellent compatibility with the ligand-substituted quantum dots.

The above-described solvent-free quantum dot composition according to the present invention has excellent optical properties such as light absorption rate and light change rate, and can realize low viscosity. Specifically, the viscosity at room temperature (25° C.) may be 30 cps or less, preferably 28 cps or less, and more preferably 25 cps or less. By adjusting the viscosity to an appropriate range, the solvent-free quantum dot composition not only has excellent workability and processability, but also has excellent storage stability at high temperatures. In addition, since the solvent-free quantum dot composition according to the present invention can be implemented with low viscosity, it can be used for inkjet printing.

<Method for producing solvent-free quantum dot composition>

In one embodiment of the present invention, a method for producing a solvent-free quantum dot composition includes the steps of (a) synthesizing quantum dots, (b) without separating the quantum dots from the solution in which the quantum dots are synthesized, and containing an ethylene glycol structure Primary surface modification of the quantum dots with a primary ligand, (c) secondary surface modification of the primary surface-modified quantum dots with a secondary ligand represented by Formula 1 below, (d) result of step (c) It may include separating and obtaining surface-modified quantum dots, and (e) dispersing the obtained surface-modified quantum dots in a photopolymerizable monomer.

[Formula 1]

(In Formula 1 above,

M is a divalent to tetravalent metal;

R ¹ to R ³ are independently hydrogen or an organic group having 3 to 70 carbon atoms;

n is an integer from 2 to 4.)

In addition, after step (c),

(f) tertiary surface modification of the modified quantum dots by adding a tertiary ligand having 3 to 40 carbon atoms including a carboxyl group.

In step (c), the modification of the quantum dots with the secondary ligand is preferably performed after the modification of the quantum dots with the primary ligand.

Here, the quantum dots, the primary ligand, the secondary ligand, the tertiary ligand, and the photopolymerizable monomer are as described above. In addition, as a method for manufacturing quantum dots, conventionally known methods (eg, a high-temperature injection method, a microfluidic reactor method, a method using microwave irradiation, etc.) may be used. In the present invention, since the composition of the ligand and its modification method in the state of the quantum dot production solution are characteristic, not the manufacturing method of the quantum dot, this will be described in detail.

Specifically, in the step (b), while the temperature of the solution in which the quantum dots were synthesized was lowered and maintained at about 80 ° C, a solution in which a primary ligand was diluted in cyclohexylacetate at 20 wt% was added and stirred for about 5 hours to perform primary modification. It may be a step to In the step (c), a solution in which the secondary ligand is diluted to 20wt% in cyclohexylacetate is added and stirred for about 90 minutes in a state where the temperature is lowered to about 30 ° C., thereby secondaryly modifying the surface of the quantum dots. . In addition, after step (c), a step of modifying the surface of the quantum dots by adding a tertiary ligand and reacting for 30 minutes to 3 hours in a state where the temperature is lowered to about 30° C. by cooling again may be included.

The surface modification step of the quantum dots can be divided into two or three steps to modify the surface of the quantum dots to prevent the formation of an adduct due to a reaction between a primary ligand, a secondary ligand, and a tertiary ligand. By first reacting with the hydrophobic quantum dots to weaken the hydrophobicity, the reaction with the secondary ligand and the tertiary ligand proceeds even in the overall hydrophobic quantum dot synthesis solution, so that the surface of the quantum dots is modified, and then the dispersibility in the photopolymerizable monomer is improved. .

On the other hand, when the secondary ligand and the tertiary ligand are simultaneously added to the quantum dot, an adduct may be formed due to a thiol-ene reaction between the thiol group of the secondary ligand and the acrylate of the tertiary ligand. . These adducts can improve the viscosity of the quantum dot composition when the surface-modified quantum dots are dispersed in the photopolymerizable monomer.

In addition, the step of modifying the surface of the quantum dots is the step of simultaneously adding the secondary ligand and the tertiary ligand to the primary surface-modified quantum dots and reacting at 25 ° C to 100 ° C for 30 minutes to 3 hours to modify the surface of the quantum dots. can be

After modifying the surface of the quantum dots by the above-described method, the surface-modified quantum dots may be obtained through centrifugation. In addition, the solvent-free quantum dot composition may be prepared by dispersing the obtained surface-modified quantum dots in a polymerizable monomer.

<Cured film, color filter and display device>

The present invention may provide a cured film comprising the above-described solvent-free quantum dot composition. The cured film according to the present invention has excellent light properties, and specifically, the light absorption rate may be 75% or more, preferably 78% or more. In addition, the cured film may have a light conversion rate of 25% or more, specifically 29% or more. In addition, when coated with a thickness of 10 ± 0.5 μm, the absolute quantum efficiency may be 30% or more.

Forming a pattern of the cured film by applying the above-described solvent-free quantum dot composition on a substrate by an inkjet spraying method; and curing the pattern.

The present invention provides a color filter comprising the above-described solvent-free quantum dot composition. A color filter is an optical component in the form of a thin film that extracts three colors of red, green, and blue in pixel units from white light emitted from a rear light source to realize color in a liquid crystal display.

Such a color filter may be manufactured by methods such as a dyeing method, a pigment dispersion method, a printing method, and an electrodeposition method. In addition, a color filter including a quantum dot composition may be prepared by an ink jet method. Since the inkjet method uses materials only for desired pixels, unnecessary waste of materials can be prevented.

In addition, the present invention provides a display device comprising the quantum dot composition described above. Here, the display device includes a liquid crystal display (LCD), an electroluminescence display (EL), a plasma display (PDP), a field emission display (FED), an organic light emitting diode (OLED), and the like, but is not limited thereto.

Hereinafter, the present invention will be described in more detail through examples. However, the following examples are only for exemplifying the present invention, and the scope of the present invention is not limited to the examples.

[Synthesis Example of Quantum Dot (QD)]

1) Dissolve zinc acetate and oleic acid in 1-octadecene in a 200 ml flask, heat to about 120° C. under vacuum, and then cool to room temperature to obtain a zinc oleate solution.

2) Heat indium acetate and lauryl acid together with the above zinc oleate to about 120° C. under vacuum in a reaction flask. The molar ratio of indium to laurylic acid is about 1:3. After about 1 hour, the atmosphere in the reactor is changed to nitrogen. While raising the temperature in the reaction flask to about 250 ° C., a mixed solution of tris (trimethylsilyl) phosphine (TMS ₃ P) and trioctylphosphine (hereinafter referred to as TOP) and optionally the zinc oleate The solution is rapidly injected into the reactor. During the reaction, an indium oleate solution, a TMS ₃ P mixed solution, and zinc oleate are sequentially injected into the reaction flask. The total reaction time is about 30 minutes.

3) Prepare a Se/TOP solution by dispersing Se in TOP at about 120°C. In addition, S is dispersed in TOP to prepare an S/TOP solution.

4) Zinc acetate and oleic acid are dissolved in trioctylamine (TOA) in a 300 mL reactor and subjected to vacuum treatment at about 120° C. for about 10 minutes to obtain a zinc precursor. After replacing the inside of the flask with nitrogen (N ₂ ), the temperature is raised to about 280° C., and the temperature is maintained for a predetermined time.

5) The prepared InZnP core and the prepared Se/TOP are added at a predetermined ratio and heated to a high temperature of about 300° C. or more to react to form a ZnSe-containing layer.

6) When the Se precursor is consumed, S/TOP and about 0.07 mmol of ZnCl ₂ are simultaneously injected. It reacts for a total of 1 hour to form a ZnS-containing layer.

7) InZnP/ZnSe/ZnS (core/shell/shell) quantum dots are made. As a final product, a solution containing the quantum dots dispersed in a hydrophobic TOA solvent and impurities such as reaction residues (oleic acid, TOP, etc.) is obtained.

[Preparation Example 1] Preparation of primary ligand

1) Thioglycolic acid 0.271mol, triethylene glycol monomethyl ether 0.276mol, and p-toluene sulfonic acid monohydrate (catalyst) 0.027mol are mixed with 350ml cyclohexane and reacted at about 80℃ for about 18 hours in a nitrogen environment.

2) When the reaction is complete, remove cyclohexane and dissolve in chloroform.

3) Neutralize with NaHCO ₃ aqueous solution and remove impurities with MgSO ₄ .

4) Residual solvent is removed to obtain methoxy triethylene glycol thioglycolate (hereinafter referred to as MTEGT or primary ligand).

[Preparation Example 2-1] Preparation of secondary ligand 2-1

1) Mercaptosuccinic acid 0.271mol, triethylene glycol butyl ether 0.276mol, p-toluene sulfonic acid monohydrate (catalyst) 0.027mol mixed with cyclohexane 350ml and reacted at about 80℃ for about 18 hours in a nitrogen environment.

2) When the reaction is complete, remove cyclohexane and dissolve in chloroform.

3) Neutralize with NaHCO ₃ aqueous solution and remove impurities with MgSO ₄ .

4) Remove the residual solvent to obtain Bis-(butoxy triethylene glycol)mercaptosuccinate (hereinafter referred to as BTEGMS).

5) Zn-(BTEGMS) ₂ is obtained as the secondary ligand 2-1 by reacting ZnCl ₂ and BTEGMS at a molar ratio of about 1:3.

[Preparation Example 2-2] Preparation of secondary ligand 2-2

1) Thioglycolic acid 0.271 mol, poly(ethylene glycol)methyl ether 550 (number average molecular weight 550 g/mol) 0.276 mol, and p-toluene sulfonic acid monohydrate 0.027 mol were mixed in 350 ml of cyclohexane and stirred in a nitrogen environment for about 18 hours at about 80 g/mol. reacted at °C.

2) When the reaction is complete, remove cyclohexane and dissolve in chloroform.

3) Neutralize with NaHCO ₃ aqueous solution and remove impurities with MgSO ₄ .

4) Residual solvent is removed to obtain PEG 550-thioglycolate (hereinafter referred to as PEG550-T).

5) Zn-(PEG550-T) ₂ is obtained as a secondary ligand 2-2 by reacting ZnCl ₂ and PEG550-T at a molar ratio of about 1:3.

[Preparation Example 2-3] Preparation of secondary ligand 2-3

In a round flask, zinc chloride (ZnCl ₂ ) and a compound represented by Formula A-1 are put into cyclohexyl acetate at a molar ratio of about 1:3 and then dissolved by thermal stirring at about 60°C. Thereafter, HCl was removed in a vacuum for about 2 hours to prepare a secondary ligand 2-3.

[A-1]

[Preparation Example 2-4] Preparation of secondary ligand 2-4

Secondary ligand 2-4 was prepared in the same manner as in Preparation Example 2-3, except that the compound represented by Formula A-2 was used instead of the compound represented by Formula A-1 in Preparation Example 2-3. .

[A-2]

[Preparation Example 2-5] Preparation of secondary ligand 2-5

Secondary ligand 2-5 was prepared in the same manner as in Preparation Example 2-3, except that the compound represented by Formula A-3 was used instead of the compound represented by Formula A-1 in Preparation Example 2-3. .

[A-3]

[Preparation Example 2-6] Preparation of secondary ligand 2-6

Secondary ligand 2-6 was prepared in the same manner as in Preparation Example 2-3, except that the compound represented by Formula A-4 was used instead of the compound represented by Formula A-1 in Preparation Example 2-3. .

[A-4]

[Preparation Example 2-7] Preparation of secondary ligand 2-7

Secondary ligand 2-7 was prepared in the same manner as in Preparation Example 2-3, except that the compound represented by Formula A-5 was used instead of the compound represented by Formula A-1 in Preparation Example 2-3. .

[A-5]

[Preparation Example 3-1] Preparation of tertiary ligand 3-1

After putting the compound represented by the following formula B-1 in cyclohexyl acetate at 20wt% in a round flask, the mixture was stirred at room temperature for about 1 hour to prepare a tertiary ligand 3-1.

[B-1]

[Preparation Example 3-2] Preparation of tertiary ligand 3-2

A tertiary ligand 3-2 was prepared in the same manner as in Preparation Example 3-1, except that the compound represented by Formula B-2 was used instead of the compound represented by Formula B-1 in Preparation Example 3-1. .

[B-2]

[Preparation Example 3-3] Preparation of tertiary ligand 3-3

Tertiary ligand 3-3 was prepared in the same manner as in Preparation Example 3-1, except that the compound represented by Formula B-3 was used instead of the compound represented by Formula B-1 in Preparation Example 3-1. .

[B-3]

[Preparation Example 3-4] Preparation of tertiary ligand 3-4

A tertiary ligand 3-4 was prepared in the same manner as in Preparation Example 3-1, except that the compound represented by Formula B-4 was used instead of the compound represented by Formula B-1 in Preparation Example 3-1. .

[B-4]

[Preparation Example 3-5] Preparation of tertiary ligand 3-5

A tertiary ligand 3-5 was prepared in the same manner as in Preparation Example 3-1, except that the compound represented by Formula B-5 was used instead of the compound represented by Formula B-1 in Preparation Example 3-1. .

[B-5]

[Preparation Example 3-6] Preparation of tertiary ligand 3-6

A tertiary ligand 3-6 was prepared in the same manner as in Preparation Example 3-1, except that the compound represented by Formula B-6 was used instead of the compound represented by Formula B-1 in Preparation Example 3-1. .

[B-6]

<Example 1> Preparation of quantum dot composition

1-1. Fabrication of quantum dots

InZnP/ZnSe/ZnS quantum dots are synthesized according to the synthesis example of the QD. It does not go through the process of separating and purifying the quantum dots from the solution in which the quantum dots are synthesized.

1-2. Surface modification of quantum dots

1) While the temperature of the solution (about 300 g) in which the quantum dots were synthesized was lowered and maintained at about 80 ° C, 6.2 g of a solution diluted with 20 wt% of MTEGT (primary ligand) according to Preparation Example 1 in cyclohexylacetate was added to about After stirring for 5 hours, the quantum dots were subjected to primary surface modification.

2) The temperature of the solution containing the primary surface-modified quantum dots was lowered to about 30 ° C, and the secondary ligand 2-1 (Zn- (BTEGMS) ₂ ) according to Preparation Example 2-1 was diluted to 20 wt% in cyclohexylacetate 0.8 g of the prepared solution was added and stirred for about 90 minutes to perform secondary surface modification.

3) Cool to room temperature to complete the reaction.

1-3. Preparation of quantum dot-monomer dispersion

1) Quantum dot powder is obtained by centrifuging the surface-modified quantum dot-containing solution with hexane and acetone.

2) QD dispersion 1 was prepared by dispersing the quantum dot powder in 1,6-hexandiol diacrylate at 50wt%.

1-4. Preparation of QD ink composition

1) A TiO ₂ dispersion was prepared by dispersing about 50wt% of TiO ₂ powder in 1,6-hexandiol diacrylate as a dispersing agent and ensuring that the 90% particle diameter (D90) in the particle size distribution did not exceed 300 nm.

2) QD Ink (Composition 1) was prepared by mixing 80 g of QD dispersion 1, 8 g of TiO ₂ dispersion, 1 g of TPO-L, and 11 g of 1,6-hexandiol diacrylate.

<Example 2> Preparation of quantum dot composition

1-1. Fabrication of quantum dots

Same as Example 1.

1-2. Surface modification of quantum dots

1) Prepare tertiary ligand 3-2 (mono (2-acryloyloxyethyl) succinate, MEAS) according to Preparation Example 3-2.

2) As in Example 1, the surface of the quantum dots is modified twice.

3) The temperature of the solution containing the secondary modified quantum dots was lowered again to about 30° C., and about 1.19 g of MEAS was added to the solution and stirred for about 90 minutes to perform tertiary surface modification of the quantum dots.

4) Cool to room temperature to complete the reaction.

1-3. Preparation of quantum dot-monomer dispersion

QD dispersion 2 was prepared in the same manner as in Example 1.

1-4. Preparation of QD ink composition

QD Ink (Composition 2) was prepared in the same manner as in Example 1, but by mixing QD Dispersion 2 instead of QD Dispersion 1.

<Example 3> Preparation of quantum dot composition

1-1. Fabrication of quantum dots

Same as Example 1.

1-2. Surface modification of quantum dots

Example 1 was performed except that Zn-(PEG550-T) ₂ (secondary ligand 2-2) was used instead of Zn-(BTEGMS) ₂ .

1-3. Preparation of quantum dot-monomer dispersion

QD dispersion 3 was prepared in the same manner as in Example 1.

1-4. Preparation of QD ink composition

QD Ink (Composition 3) was prepared in the same manner as in Example 1, but by mixing QD Dispersion 3 instead of QD Dispersion 1.

<Example 4> Preparation of quantum dot composition

1-1. Fabrication of quantum dots

Same as Example 1.

1-2. Surface modification of quantum dots

Example ₂ was performed except that Zn-(PEG550-T) ₂ (secondary ligand 2-2) was used instead of Zn-(BTEGMS) 2 .

1-3. Preparation of quantum dot-monomer dispersion

QD dispersion 4 was prepared in the same manner as in Example 1.

1-4. Preparation of QD ink composition

QD Ink (Composition 4) was prepared in the same manner as in Example 1, but by mixing QD Dispersion 4 instead of QD Dispersion 1.

<Example 5> Preparation of quantum dot composition

1-1. Fabrication of quantum dots

Same as Example 1.

1-2. Surface modification of quantum dots

The same procedure as in Example 3 was performed except that 1.56 g of a solution in which Zn-(PEG550-T) ₂ (secondary ligand 2-2) was diluted to 20wt% in cyclohexylacetate was used.

1-3. Preparation of quantum dot-monomer dispersion

QD dispersion 5 was prepared in the same manner as in Example 1.

1-4. Preparation of QD ink composition

QD Ink (Composition 5) was prepared in the same manner as in Example 1, but by mixing QD Dispersion 5 instead of QD Dispersion 1.

<Example 6> Preparation of quantum dot composition

1-1. Fabrication of quantum dots

Same as Example 1.

1-2. Surface modification of quantum dots

The same procedure as in Example 4 was performed except that 1.56 g of a solution in which Zn-(PEG550-T) ₂ (secondary ligand 2-2) was diluted to 20wt% in cyclohexylacetate was used.

1-3. Preparation of quantum dot-monomer dispersion

QD dispersion 6 was prepared in the same manner as in Example 1.

1-4. Preparation of QD ink composition

QD Ink (Composition 6) was prepared in the same manner as in Example 1, but by mixing QD Dispersion 6 instead of QD Dispersion 1.

<Comparative Example 1> Preparation of quantum dot composition

1-1. Fabrication of quantum dots

Same as Example 1.

1-2. Surface modification of quantum dots

While the temperature of the solution (about 300 g) in which the quantum dots were synthesized was lowered and maintained at about 50 ° C, 6.4 g of a solution diluted with 20 wt% of 2- (2-Methoxyethoxy) acetic acid (hereinafter referred to as MEAA) in cyclohexylacetate was added. The surface of the quantum dots was modified by stirring for about 5 hours. The reaction was terminated by cooling to room temperature.

1-3. Preparation of quantum dot-monomer dispersion

QD comparative dispersion 1 was prepared in the same manner as in Example 1.

<Comparative Example 2> Preparation of quantum dot composition

1-1. Fabrication of quantum dots

Same as Example 1.

1-2. Quantum dot surface layering step

Quantum dots were modified in the same manner as in Comparative Example 1, except that MTEGT was used instead of MEAA.

1-3. Preparation of quantum dot-monomer dispersion

In the same way as in Example 1 QD comparative dispersion 2 was prepared.

1-4. Preparation of QD ink composition

QD Ink (Comparative Composition 2) was prepared in the same manner as in Example 1, but by mixing QD Comparative Dispersion 2 instead of QD Dispersion 1.

<Comparative Example 3> Preparation of quantum dot composition

1-1. Fabrication of quantum dots

Quantum dots are prepared in the same manner as in Example 1, but the solution containing the synthesized quantum dots is cooled to room temperature and centrifuged with ethanol and acetone to obtain quantum dot powder.

1-2. Surface modification of quantum dots

1) Disperse the quantum dot powder in cyclohexylacetate at about 20wt%.

2) The temperature of the dispersed quantum dot solution (about 100 g) was raised to about 60 ° C and maintained, and about 15 g of Zn- (BTEGMS) ₂ (secondary ligand 2-1) was injected and stirred for about 3 hours to obtain the first surface modified.

3) Subsequently, 100 g of a solution in which MEAS (tertiary ligand 3-2) was diluted to about 20 wt% in cyclohexylacetate was added and stirred for about 3 hours to perform secondary surface modification.

4) The reaction is terminated by cooling to room temperature.

1-3. Preparation of quantum dot-monomer dispersion

QD comparative dispersion 3 was prepared in the same manner as in Example 1.

1-4. Preparation of QD ink composition

QD Ink (Comparative Composition 3) was prepared in the same manner as in Example 1, but by mixing QD Comparative Dispersion 3 instead of QD Dispersion 1.

<Comparative Example 4> Preparation of quantum dot composition

1-1. Fabrication of quantum dots

Same as Comparative Example 3.

1-2. Surface modification of quantum dots

Same as Comparative Example 3 except that about 30 g of Zn-(PEG550-T) ₂ (secondary ligand 2-2) was used instead of Zn-(BTEGMS) ₂ (secondary ligand 2-1) in the first surface modification step. do.

1-3. Preparation of quantum dot-monomer dispersion

QD comparative dispersion 4 was prepared in the same manner as in Example 1.

1-4. Preparation of QD ink composition

QD Ink (Comparative Composition 4) was prepared in the same manner as in Example 1, but by mixing QD Comparative Dispersion 4 instead of QD Dispersion 1.

Examples 1 to 6 and Comparative Examples 1 to 4 are summarized in Table 1 below.

<Test Example 1> Measurement of dispersibility, absolute quantum efficiency (QE), emission wavelength and full width at half maximum of QD dispersion

QD dispersions 1 to 6 and QD comparative dispersions 1 to 4 obtained in Examples 1 to 6 and Comparative Examples 1 to 4 were examined for QD precipitation to confirm dispersibility, and the absolute quantum efficiency of the QD dispersions QE (Otsuka, QE-2000 ), wavelength and full width at half maximum were measured. The results are shown in Table 2 below.

As shown in Table 2, when only one type of MEAA was used in the solution in which the quantum dots were synthesized (QD comparative dispersion 1), it was confirmed that the dispersibility of QDs decreased due to the polarity of the monomers after ligand substitution and precipitation occurred. . Other than that, the dispersibility was good without precipitate (Clear).

When comparing QD comparative dispersions 1 and 2 using only one ligand, only QD comparative dispersion 2 was dispersible, which means that MTEGT (QD comparative dispersion 2) has more repeated ethylene glycol structures than MEAA (QD comparative dispersion 1). It is believed that the QD surface was modified to be more hydrophilic, thereby improving the dispersibility.

Compared to QD comparative dispersion 2 using only one primary ligand (MTEGT), when two or more ligands were used, such as QD dispersions 1 to 6, the QE values were all over 99.4%, so when two or more ligands were used, the absolute quantum It was confirmed that the efficiency was slightly better.

Significant difference in QE value when comparing the case where ligand substitution was performed immediately after synthesis of quantum dots (QD dispersions 1 to 6) and the case where ligand substitution was performed on separated and purified QDs after synthesis (QD comparative dispersions 3 and 4) It was confirmed that there is no or better. Likewise, it was confirmed that both the QD dispersion/comparative dispersion had an emission wavelength of about 523 to 524 nm and a half width of 39 to 40 nm, which were almost similar values.

Therefore, according to the present invention, ligand substitution is possible immediately after QD synthesis, and QD dispersibility and QE do not decrease accordingly. There was no significant difference in performance or there was a better aspect.

<Test Example 2> Confirmation of viscosity, light absorption and QE of the prepared composition

The viscosity of the QD Ink compositions/comparative compositions prepared in Examples 1 to 6 and Comparative Examples 2 to 4 was measured for 2 minutes at 100 rpm at room temperature (25° C.) using a viscometer (RheoStress MARS-40, manufactured by HAAKE), and the The results are shown in Table 3 below.

The QD Ink composition/comparative composition prepared in Examples 1 to 6 and Comparative Examples 2 to 4 was applied on a glass substrate to a thickness of 10 μm by a spin coating method (spin coater, Mikasa, Opticoat MS-A150) and irradiated with 395 nm UV. and exposed to light at 4000 mJ (83° C., 4 seconds) to prepare a cured film. A 2 cm x 2 cm single-film specimen was loaded into an integrating sphere equipment (QE-2100, otsuka electronics), the initial light absorption was measured and the QE was measured (Otsuka, QE-2000). Thereafter, QE was measured after heat treatment (Post-Bake) at 180 ° C. for 30 minutes under a nitrogen atmosphere. The results are shown in Table 3 below.

Although not shown in Table 3, in the case of surface modification with Zn-(BTEGMS) ₂ (secondary ligand 2-1) directly in the solution synthesized with quantum dots without primary surface modification with MTEGT (primary ligand), quantum dots No surface modification was made. Therefore, it seems that the first surface modification with MTEGT is necessary for the second or third surface modification.

As shown in Table 3, compositions 1 to 6 using two or more ligands have a smaller difference in QE values before and after heat treatment than Comparative Composition 2 using only one ligand, and thus have excellent stability (reliability) against an external heat source, and QD composition It was confirmed that the QD performance can be well maintained in the subsequent heat treatment process required for product production using .

This characteristic is due to the fact that metal-bonded secondary ligands (Zn-(BTEGMS) ₂ , Zn-(PEG550-T) ₂ ) have a higher binding force with QDs than non-metal-bonded primary ligands (MTEGT), which makes it easier to adhere to the QD surface. It is believed that this is because the ligand is bound more stably and the detachment of the ligand is reduced.

When comparing compositions 1, 3, and 5 using two ligands and compositions 2, 4, and 6 using three ligands, respectively, compositions 2, 4, and 6 have lower viscosities, and the difference in QE values before and after heat treatment is higher. It was confirmed that less When a tertiary ligand is added, this property induces detachment of the primary or secondary ligand that is simply physically attached without binding to the QD surface, resulting in aggregation between ligands or between ligands and 1,6-hexandiol diacrylate. ) appears to be prevented.

Compositions 3 and 4 using the secondary ligand 2-2 have slightly higher viscosities than those of Compositions 1 and 2, at 25 cps or more, and a larger difference in QD values before and after heat treatment. This seems to be because the molecular weight of Zn-(PEG550-T) ₂ as the secondary ligand 2-2 is relatively high, and the molar equivalent of the secondary ligand 2-2 bound to the QD surface is relatively small compared to Compositions 1 and 2.

In order to solve this problem, compositions 5 and 6 had the same ligand composition as compositions 3 and 4, but the secondary ligand 2-2 was added twice to modify the QD. Compositions 5 and 6 were confirmed to have lower viscosity and improved light absorption when compared to compositions 3 and 4, respectively, and the degree of retention of the QE value before and after heat treatment was greatly improved. In addition, when comparing Compositions 5 and 6, Composition 6, which was subjected to tertiary modification with a tertiary ligand, exhibited better viscosity and optical properties. Therefore, those skilled in the art will be able to adjust the addition amount of the secondary ligand and whether or not to add the tertiary ligand in consideration of the necessary viscosity and the reliability of the QE value.

The viscosity, light absorption rate, and QE values (UV curing, curing, and heat treatment) of Compositions 1, 2, 5, and 6, in which ligand substitution was performed immediately after QD synthesis, were similar to those of Comparative Compositions 3 and 4 using separated and purified QDs. or was found to be superior. Therefore, it was confirmed that ligand substitution is possible in the solution immediately after QD synthesis, and accordingly, the viscosity of the composition can be further lowered, and the light absorption rate and QE do not decrease.

It is obvious to those skilled in the art that the present invention is not limited to the above embodiments and can be variously modified or modified without departing from the technical gist of the present invention. it did

Claims (35)

(a) synthesizing quantum dots; (b) first surface-modifying the quantum dots with a primary ligand having an ethylene glycol structure without separating the quantum dots from the solution in which the quantum dots were synthesized; (c) secondarily surface-modifying the first surface-modified quantum dots with a second ligand represented by Chemical Formula 1 below; [Formula 1]

(In Formula 1 above, M is a divalent to tetravalent metal; R ¹ to R ³ are independently hydrogen or an organic group having 3 to 70 carbon atoms; n is an integer from 2 to 4.) (d) obtaining surface-modified quantum dots from the product of step (c); and (e) dispersing the obtained surface-modified quantum dots in a photopolymerizable monomer: a method for producing a solvent-free quantum dot composition comprising the. The method of claim 1, After step (c), (f) tertiary surface modification of the modified quantum dots by adding a tertiary ligand having 3 to 40 carbon atoms including a carboxyl group: Method for producing a solvent-free quantum dot composition comprising. The method of claim 1, The primary ligand has a molecular weight of 100 g / mol to 500 g / mol, and a method for producing a solvent-free quantum dot composition, characterized in that it comprises an ethylene glycol structure in 1 to 5 repeating units. The method of claim 1, In Formula 1, at least one of R ¹ to R ³ repeatedly includes an ethylene glycol structure, The number of repeating units of the total ethylene glycol structure included in R ¹ to R ³ is 2 to 15, Method for producing a solvent-free quantum dot composition, characterized in that an organic group of C1 to C15 is bonded to the terminal of the ethylene glycol structure. The method of claim 2, The tertiary ligand is a method for producing a solvent-free quantum dot composition represented by Formula 2 below. [Formula 2]

(In Formula 2 above, L is a single bond or is selected from the group consisting of a substituted or unsubstituted C1 to C20 alkylene group and a substituted or unsubstituted C1 to C20 alkenylene group; A is a single bond, or ester (-C(=O)O-), ether (-O-), carbonyl (-C(=O)-), sulfonyl (-SO ₂ -), sulfide (- A C1 to C20 alkylene or alkenylene group containing at least one functional group selected from the group consisting of S-) and sulfoxide (-SO-), R is hydrogen or is selected from the group consisting of a substituted or unsubstituted C1 to C20 alkyl group and a substituted or unsubstituted C1 to C20 alkenyl group.) According to claim 1 or claim 2, The mixing ratio of the quantum dots and the total ligand is 1: 1 to 1: 20 weight ratio, method for producing a solvent-free quantum dot composition. The method of claim 1, The molar ratio of the primary ligand and the secondary ligand added to the solution is 1: 1 to 1: 20, a method for producing a solvent-free quantum dot composition. The method of claim 2, The molar ratio of the primary ligand, secondary ligand and tertiary ligand added to the solution is 1: 1 to 20: 1 to 30, a method for producing a solvent-free quantum dot composition. The method of claim 1, The primary ligand is at least one selected from the group consisting of methoxy triethylene glycol thioglycolate and 2- (2-methoxyethoxy) acetic acid, Method for producing a solvent-free quantum dot composition. The method of claim 1, The secondary ligand is zinc-(3-methoxybutyl 3-mercaptopropionate) ₂ (Zn-(3-methoxybutyl 3-mercaptopropionate) ₂ ), zinc-(3-methoxybutyl thioglycolic acid) ₂ (Zn- (3-methoxybutyl thioglycolate) ₂ ), zinc-(2-ethylhexyl thioglycolate) ₂ (Zn-(2-ethylhexyl thioglycolate) ₂ ), zinc-(butyl mercaptopropionate) ₂ (Zn-(butyl mercaptopropionate) ₂ ), zinc-(isopropyl mercaptopropionate) ₂ (Zn-(isopropyl mercaptopropionate) ₂ ), zinc-(bis-(butoxy triethylene glycol) mercapto succinic acid) ₂ (Zn-(Bis-(butoxy triethylene glycol) At least one solvent-free quantum dot composition selected from the group consisting of mercapto succinate) ₂ ) and zinc-(poly(ethylene glycol)methyl ether-thioglycolic acid) ₂ (Zn-(poly(ethylene glycol)methyl ether-thioglycolate) ₂ ) Manufacturing method of. The method of claim 2, The tertiary ligand is 2-carboxyethyl acrylate, mono-2-(acryloyloxy)ethyl succinate, mono-2-(methacryloyloxy) C) ethyl succinate (mono-2-(methacryloyloxy)ethyl succinate), mono-2-(methacryloyloxy)ethyl maleate, 2-[2-(2- Composed of 2-[2-(2-methoxyethoxy)ethoxy]acetic acid and 2-(2-methoxyethoxy)acetic acid At least one selected from the group, a method for producing a solvent-free quantum dot composition. The method of claim 1, The solution contains fatty acids, fatty acid derivatives, by-products of the quantum dot synthesis reaction, dioctyl octadecenamide, trioctylphosphine and its oxides, n-octadecene, trioctylamine ), metal acetate, metal oleate, tris(trimethylsilyl)phosphine, selenium (Se), sulfur (S), selenium-trioctylphosphine, sulfur-trioctylphosphine, chlorine salt A method for producing a solvent-free quantum dot composition comprising at least one selected from the group consisting of (chloride salt) and metal chloride. The method of claim 1, The photopolymerizable monomer is 1,6-hexanediol diacrylic acid (1,6-hexandiol diacrylate), a method for producing a solvent-free quantum dot composition. Including quantum dots and photopolymerizable monomers, The quantum dots may include a primary ligand including an ethylene glycol structure; and A secondary ligand represented by Formula 1: A solvent-free quantum dot composition that is surface-modified with. [Formula 1]

(In Formula 1 above, M is a divalent to tetravalent metal; R ¹ to R ³ are independently hydrogen or an organic group having 3 to 70 carbon atoms; n is an integer from 2 to 4.) The method of claim 14, The surface-modified quantum dot is a solvent-free quantum dot composition that is surface-modified with a tertiary ligand having 3 to 40 carbon atoms including a carboxyl group. According to claim 14 or 15, Characterized in that the surface modification of the quantum dots is made in a solution in which the synthesis of the quantum dots has occurred, the solvent-free quantum dot composition. The method of claim 14, The primary ligand has a molecular weight of 100 g / mol to 500 g / mol, and a solvent-free quantum dot composition, characterized in that it comprises an ethylene glycol structure in 1 to 5 repeating units. The method of claim 14, In Formula 1, at least one of R ¹ to R ³ repeatedly includes an ethylene glycol structure, The number of repeating units of the total ethylene glycol structure included in R ¹ to R ³ is 2 to 15, A solvent-free quantum dot composition, characterized in that an organic group of C1 to C15 is bonded to the terminal of the ethylene glycol structure. The method of claim 15 The tertiary ligand is a solvent-free quantum dot composition represented by Formula 2 below. [Formula 2]

(In Formula 2 above, L is a single bond or is selected from the group consisting of a substituted or unsubstituted C1 to C20 alkylene group and a substituted or unsubstituted C1 to C20 alkenylene group; A is a single bond, or ester (-C(=O)O-), ether (-O-), carbonyl (-C(=O)-), sulfonyl (-SO ₂ -), sulfide (- A C1 to C20 alkylene or alkenylene group containing at least one functional group selected from the group consisting of S-) and sulfoxide (-SO-), R is hydrogen or is selected from the group consisting of a substituted or unsubstituted C1 to C20 alkyl group and a substituted or unsubstituted C1 to C20 alkenyl group.) The method of claim 14, The primary ligand is at least one selected from the group consisting of methoxy triethylene glycol thioglycolate and 2- (2-methoxyethoxy) acetic acid, Solvent-free quantum dot composition. The method of claim 14, The secondary ligand is zinc-(3-methoxybutyl 3-mercaptopropionate) ₂ (Zn-(3-methoxybutyl 3-mercaptopropionate) ₂ ), zinc-(3-methoxybutyl thioglycolic acid) ₂ (Zn- (3-methoxybutyl thioglycolate) ₂ ), zinc-(2-ethylhexyl thioglycolate) ₂ (Zn-(2-ethylhexyl thioglycolate) ₂ ), zinc-(butyl mercaptopropionate) ₂ (Zn-(butyl mercaptopropionate) ₂ ), zinc-(isopropyl mercaptopropionate) ₂ (Zn-(isopropyl mercaptopropionate) ₂ ), zinc-(bis-(butoxy triethylene glycol) mercapto succinic acid) ₂ (Zn-(Bis-(butoxy triethylene glycol) mercapto succinate) ₂ ) and zinc-(poly(ethylene glycol)methyl ether-thioglycolic acid) ₂ (Zn-(poly(ethylene glycol)methyl ether-thioglycolate) ₂ ), solvent-free quantum dot composition at least one selected from the group consisting of . The method of claim 15 The tertiary ligand is 2-carboxyethyl acrylate, mono-2-(acryloyloxy)ethyl succinate, mono-2-(methacryloyloxy) C) ethyl succinate (mono-2- (methacryloyloxy) ethyl succinate), mono-2- (methacryloyloxy) ethyl maleate (mono-2- (methacryloyloxy) ethyl maleate), 2- [2- (2- Composed of 2-[2-(2-methoxyethoxy)ethoxy]acetic acid and 2-(2-methoxyethoxy)acetic acid At least one selected from the group, solvent-free quantum dot composition. The method of claim 14, Wherein M is Mg, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Sr, Mo, Pd, Cd, In or Sn, solvent-free quantum dot composition. The method of claim 14, The M is Zn, solvent-free quantum dot composition. The method of claim 14, The molar ratio of the primary ligand and the secondary ligand is 1:1 to 1:20, solvent-free quantum dot composition. The method of claim 15 The molar ratio of the primary ligand, secondary ligand and tertiary ligand is 1: 1 to 20: 1 to 30, a solvent-free quantum dot composition. According to claim 14 or claim 15, The composition ratio of the quantum dots and the ligand is 1: 1 to 1: 20 weight ratio, solvent-free quantum dot composition. The method of claim 14, The photopolymerizable monomer is a (meth) acrylate-based monomer, a solvent-free quantum dot composition. The method of claim 14, The photopolymerizable monomer is 1,6-hexanediol diacrylic acid (1,6-hexandiol diacrylate), a solvent-free quantum dot composition. According to claim 14 or claim 15, A solvent-free quantum dot composition having a viscosity of 30cps or less. According to claim 14 or claim 15, A solvent-free quantum dot composition used for inkjet printing. A cured film prepared using the solvent-free quantum dot composition according to claim 14 or claim 15. The method of claim 32 A cured film having an absolute quantum efficiency of 30% or more when the solvent-free quantum dot composition is coated to a thickness of 10 ± 0.5 μm. A color filter comprising the solvent-free quantum dot composition according to claim 14 or claim 15. A display device comprising the color filter according to claim 34 .